One of the most intriguing discoveries is that many risk factors for Cardiovascular, Type-1 Diabetes and Type-2 Diabetes diseases can be risk factors for Alzheimer's disease (also known as Type-3 Diabetes disease). High blood cholesterol levels are important risk factors for Alzheimer's disease. If blood flow is restricted because of plaque accumulation/buildup in a human brain, less oxygen gets to a human brain and fewer waste residues leave a human brain.
Type-1 Diabetes disease can be caused by autoimmune destruction of insulin-producing cells in the pancreas, resulting in high blood sugar. The drugs that block effector-memory T cells can delay and/or prevent Type-1 Diabetes disease.
Type-2 Diabetes disease can be linked to excessive iron, diseased pancreas and metabolic syndrome/obesity-hence macrophages in fat tissues. The macrophages in fat tissues produce cytokine molecules, which can cause inflammations in the pancreas. Such inflammations in the pancreas can increase the insulin (a hormone needed to convert carbohydrates, foods and glucose into energy needed for daily life) resistance and gradually the pancreas loses its ability to produce insulin. Type-2 Diabetes disease is marked by high levels of blood glucose resulting from defects in glucose production and/or glucose inaction and/or insulin production and/or insulin inaction. Type-2 Diabetes disease and obesity can be linked with cryptochrome, a protein. Cryptochrome can regulate/modulate/synchronize the biological clock and glucose level in a human body. An increased level of cryptochrome can suppress/inhibit the production of enzymes (in the liver) for glucose generation during fasting (gluconeogenesis). Bioactive compounds and/or bioactive molecules that enhance the activity of calcineurin/NFAT can be effective against Type-2 Diabetes disease, wherein the beta cells do not produce enough insulin. Type-2 Diabetes disease is caused by insufficient numbers of insulin-producing beta cells. But Type-2 Diabetes disease not only lacks insulin, but also produces too much glucagon. Normally, about 50% of the insulin produced by the pancreas is immediately destroyed by the liver; but there may be a mechanism to regulate how much insulin enters the bloodstream. Insulin degrading enzyme (IDE) is a protease, an enzyme that chops proteins or peptides into smaller pieces. If insulin degrading enzyme is inhibited, insulin can remain in the blood stream longer. Insulin is involved in a surprisingly wide range of important processes, including memory and cognition, thus insulin degrading enzyme inhibitors may have multiple therapeutic applications. Insulin degrading enzyme is a thiol-sensitive zinc-metallopeptidase.
Both Type-1 and Type-2 Diabetes diseases can lead to serious complications (e.g., high blood pressure, kidney disease and premature death). But people with Type-1 and Type-2 Diabetes diseases can control/manage the diseases to lower the risks of serious complications.
The risk of Alzheimer's disease can be linked with obesity and Type-2 Diabetes disease. SorCS1 transport protein can control how the insulin receptor moves around a cell/neuron. Deficiency in SorCS1 transport protein can increase the risk of developing Alzheimer's disease, because amyloid precursor protein (APP) spends too much time in the region of the neuron wherein amyloid precursor protein is broken down into amyloid beta protein. A human brain has a low antioxidant level and requires a large volume of blood pumped through it to function properly. The biochemical reaction of glucose (in blood) with proteins is known as glycation. Glycation can cause problems in a human brain. The glucose molecule can be split/divided open by enzymes for energy consumption in a human brain and two (2) reactive aldehydes can crosslink with proteins in a human brain-thus leading to a decreased blood flow. Another possible link is leptin, a hormone. Leptin is released by fat cells in a human body and acts on the leptin receptors in a human brain to regulate hunger. There are a number of leptin receptors all over a human body including in the hypothalamus of a human brain. Higher level of leptin can suppress appetite and enhance metabolism. Leptin also plays a key role in modulating insulin. But obesity can create leptin resistance-thus leptin is not transported efficiently in a human brain. Higher levels of leptin in a human brain may lower the risk of developing Alzheimer's disease. Leptin can also reduce the production of amyloid beta protein, wherein amyloid beta protein is involved in Alzheimer's disease. Although obesity is often associated with insulin resistance and Diabetes disease, this is not always the case. However, when T-bet protein is absent, the relationship between fat and insulin resistance can be altered. T-bet is a protein that regulates the differentiation and function of immune cells.
Clinical and epidemiological studies have found that Type-2 Diabetes disease and hyperinsulinaemia, increased the risk of developing Alzheimer's disease. The link between hyperinsulinaemia and Alzheimer's disease may be insulin degrading enzyme. This enzyme degrades both insulin and amylin peptides related to the pathology of Type-2 Diabetes disease along with amyloid-beta peptide, a short peptide found in excess in the Alzheimer's brain.